“There are several Sikhs active in politics in America, but it’s not nearly at the same level as in Canada,” said Balpreet Singh, a Toronto-based member of the World Sikh Organization. “Personally, I think the political climate has a lot to do with it. Candidates there feel, let’s be honest, the need to highlight their Christianity.”

Facing down a gunman in the kitchen of the gurdwara he helped found, Satwant Singh Kaleka picked up a nearby butter knife and tried to fend the man off. He was shot twice in the leg and mortally wounded in the rampage at the Sikh temple in Oak Creek, Wis., but his action bought precious time for others to escape and call police.

This account of Mr. Kaleka’s final moments, conveyed to reporters by his son, Amardeep, was in keeping with the 65-year-old temple president’s character as a leader in his community, where he worked to help the local Sikh population and educate others about his faith. His nephew, Gurinder Nagra, said Mr. Kaleka was always pleased when non-Sikhs would visit the temple.

“He’d tell them what our rituals are, what do we preach and all this stuff,” Mr. Nagra recalled. “His soul was in the temple all the time, and that’s where he ended his life. He sacrificed his life for peace and love.”

Oak Creek police officers, meanwhile, demonstrated further heroism. The first on the scene, Lieutenant Brian Murphy, jumped out of his car to help an injured person in the driveway. The gunman Wade Michael Page allegedly walked up and unloaded nine rounds into the 21-year police veteran. But even as Lt. Murphy lay bleeding, he told fellow officers to leave him and tend to the other wounded.

“As they approached him, he waved them off,” police chief John Edwards told a news conference. “He told them to go into the temple and assist those in there.”

Another officer, identified by the Associated Press as Sam Lenda, killed Mr. Page with a rifle. Lt. Murphy remains in hospital, where he is expected to survive; Mr. Lenda was unhurt.

And even as the United States grappled with the tragedy – in which six people, as well as the gunman, died – Americans also sought to learn more about Sikhs themselves. Their religion is little understood in the United States, where some people even conflate it with Islam. Chief Edwards, for instance, called up a Sikh man to clarify the pronunciation of the Punjabi names of the dead. And American media outlets had to include basic primers on Sikhism with their coverage of the disaster.

This is what sets apart Sikh experiences in Canada and the United States.

Sikh communities in both countries share much common history. The earliest immigrants gathered on the West Coast, in British Columbia and California, in the late 19th and early 20th centuries. Subsequent waves of Sikhs in the 1970s and 1980s settled across the continent, particularly in Toronto, Chicago and the U.S. East Coast.

But while Sikhs in Canada have attained a measure of influence – they have been elected to Parliament, served in federal cabinets, won the right to wear turbans as police officers and regularly see tens of thousands at Khalsa Day parades – their counterparts south of the border have far less visibility.

Rupinder Mohan Singh, a 38-year-old health-care administrator who grew up in Canada and now lives in the San Francisco area, cites two reasons for the difference. The first is demographic: Both countries have similar numbers of Sikhs, thought to be close to half a million, but they make up a much smaller proportion of the general population in the United States. The second, he said, is Canada’s embrace of multiculturalism.

“In Canada, Sikhs are known of a known quantity, there’s a much higher familiarity and comfort level with who Sikhs are. They can walk around and people won’t really look twice, for the most part,” he said. “In the United States …people look at a Sikh and they don’t know: Who is this turbaned, bearded man? Who is this woman who is covering her hair or wearing traditional clothes?”

When he moved to the United States a decade ago, Mr. Singh was even the target of Islamophobic slurs, shouted from car windows or whispered by shoppers at the mall, from people who mistook him for a Muslim.

He said Sikhs themselves have reacted to the American melting pot by being a little more subtle about their identities than their Canadian brethren and going out of their way to prove their patriotism.

Such a display was evident on the lawn of Mr. Kaleka’s home, where he erected a large flagpole to fly the Stars and Stripes. It is also illustrated in the political arena.

In Canada, for instance, many Sikh politicians wear articles of faith – uncut beards, turbans and kirpans – and political parties openly court the community at election time. In the United States, the highest-ranking politician of Sikh heritage, South Carolina Governor Nikki Haley, identifies as a Christian and her previous faith played little part in her election.

“There are several Sikhs active in politics in America, but it’s not nearly at the same level as in Canada,” said Balpreet Singh, a Toronto-based member of the World Sikh Organization. “Personally, I think the political climate has a lot to do with it. Candidates there feel, let’s be honest, the need to highlight their Christianity.”

Harjinder Singh Sandhu, 45, who has lived in several cities in both countries, suggests another difference between the two countries. In the Vancouver and Toronto areas, Sikhs have gravitated to particular neighbourhoods while in Chicago and Boston, where he subsequently lived, the populations are more spread out. While this could lead to greater integration, he says it also makes the community less recognizable.

Mr. Sandhu offers several anecdotes that reflect the differences in perceptions of Sikhs between the two countries. On one occasion while picking his wife up from work in Toronto, a security guard at her office mistakenly thought he was her taxi driver; in the United States, on the other hand, strangers in public will greet him with a “Salaam alaikum” – a traditional greeting among Muslims.